The purpose of this proposal is to investigate means to identify and inform couples who may wish to utilize prenatal diagnosis for sickle cell anemia or for Beta-thalassemia before the birth of their first affected child. Specifically, we intend to provide testing and genetic counseling for sickle trait and for Beta-thalassemia trait to pregnant women and, as a result: 1. To determine the frequency with which women identified as carriers during pregnancy refer their mates for carrier testing. 2. To compare two videotapes especially designed for trait counseling during pregnancy for effectiveness in inducing mate referral. 3. To identify factors predictive of mate referral which may be useful for increasing the effectiveness of future screening programs.